IRCAL Exposure Time Calculator

Select options for the exposure signal to noise calculation:

This calculation uses measured instrumental zero points and estimated backgrounds to calculate the signal to noise in IRCAL/Lick AO observations. Currently only point sources in imaging mode are supported; more modes may be added in the future.

This code is experimental and not yet fully verified against real observations; consider all numbers to be uncertain by a factor of about two for the time being. Please direct all questions, comments, or suggestions to Marshall Perrin.

Specify the exposure calculation parameters:

Find S/N ratio reached in an exposure time of seconds, times coadd(s).
Find exposure time needed to obtain a S/N ratio of

Specify the target parameters:

Observing Wavelength:
Target Type:
Target Magnitude:
Airmass: